Device for selectively setting type bars of calculating machines

ABSTRACT

In a calculating machine of the type disclosed when no numeral or decimal point is printed, no signal is transmitted to the printing device or non-printing signals are transmitted thereto so that a type bar is lifted to its uppermost position. In this position, a type bar stopper provided upon a guide plate which serves to prevent the lateral vibrations of the type bar and to guide a hammer engages with an engaging member formed upon the type bar. In consequence, the type bar is prevented from striking a paper, that is, is locked in non-printing position. The conventional type bar locking elements may be eliminated.

United States Patent Murakami Nov. 13, 1973 [54] DEVICE FOR SELECTIVELY SETTING 3,427,963 2/1969 Hesse a1 101/93 TYPE BARS 0 CALCULATING MACHINES 3,304,859 2/1967 Schenk 101/102 2,100,213 11/1937 Garbe11 101/93 [75] Inventor: Takashi Murakami, Setagaya-ku,

Tokyo Japan Primary Examiner-Wi11iam B. Penn 73 Assignee; Ricoh Ltd" Tokyo, japan Attorney-Henry T. Burke, Robert Scobey, Robert S. Dunham, P. E. Henninger, Lester W. Clark, Gerald [22] Flled: Sept 1970 W. Griffin, Thomas F. Moran, R. Bradlee Boa] and [21] APPL 73 97 Christopher C. Dunham [30] Foreign Application Priority Data [57] {\BSTRACT Sept 24 1969 Ja an 44/9121; In a calculating machine of the type disclosed when no Y p numeral or decimal point is printed, no signal is trans- [52] 101/94 mitted to the printing device or non-printing signals [51] Int 25/00 are transmitted thereto so that a type bar is lifted to its [58] Field 0 Search lol/gs MM 93 R uppermost position. In this position, a type bar stopper C 94 provided upon a guide plate which serves to prevent the lateral vibrations of the type bar and to guide a [56] References Cited hammer engages with an engaging member formed upon the type bar. In consequence, the type bar is pre- UNlTED STATES PATENTS vented from striking a paper, that is, is locked in nongg f printing position. The conventional type bar locking CVIS l t b t 2,821,909 2/1958 Grosse 101/93 e emen S may 6 e lmma 6 2,832,283 4/1958 Westinger et al....... 101/93 2 Claims, 4 Drawing Figures PATENTEDHHY 1 3 i973 SHEET 10$ 3 INVENTOR. TA/(ASH/ Ml/FAk/W/ PATENTEDHUY 13 I973 3,77 1 444 SHEET 2 BF 3 INVENTOR. TAKASH/ MU/M/(A M/ BY j W F DEVICE FOR SELECTIVELY SETTING TYPE BARS OF CALCULATING MACHINES BACKGROUND OF THE INVENTION The present invention relates to generally a mechanical or electronic calculating machine and more particularly a device for use in a mechanical or electronic calculating machine for selectively'setting type bars in printing or non-printing position.

Prior art devices of the type such as described in US. Pat. No. 3,410,484 are very complex in construction and expensive to manufacture, maintain and repair. For instance, in one prior art device of the type described, when a rack carrying a type bar which is not needed to strike a paper is prevented from rising, one end of a crank-shaped lever engages with a notch formed at the top of the rack while the other end of the lever engages with the projection of a hammer, thereby preventing the movement thereof. In other words, the prior art device needs some additional elements in addition to the hammer and rack in order to selectively prevent the printing action of the type bar.

SUMMARY OF THE INVENTION It is therefore the primary object of the present invention to provide a device for use in mechanical and electronic calculating machines for selectively setting type bars in printing or non-printing position, which device eliminates the use of additional complex elements, and is very economical to manufacture, maintain and repair.

In general, the present invention involves the provision of a type bar stopper in the form of a bent edge on a guide plate which serves to guide the type bar springloaded hammer for pivoting the type bar to printing position, and a cooperating engaging member on the type bar for engagement with the type bar stopper to prevent the pivoting of the type bar. When it is desired to lock the type bar in non-printing position, no signal is transmitted to the printing device or non-printing signal is transmitted to the device so that'the type bar is lifted to its uppermost position. In this case, the type bar stopper engages with the engaging member of the type bar so that the type bar is locked against pivoting in a non-printing position.

The present invention will become more apparent in the following description of the preferred embodiment thereof taken in conjunction with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING DESCRIPTION OF THE PREFERRED EMBODIMENT A type bar 2 for printing a desired numeral of each digit upon a paper wrapped around a platen 11 is pivotably fixed at axis a to a rack 1 having teeth b and is adapted to move vertically in unison with the rack 1. A bent portion d at the leading end of a hammer 9 is fitted into an elongated slot 2a formed in the type bar 2 having a detent c. A fork-shaped rack stopper 8 having pawls 8a and for engagement with the teeth b of the rack 1 is biased by a spring 8b to rotate the stopper 8 in the counterclockwise direction in FIG.2. A magnet arm 6 having a leading end 6a for engagement with the pawl 8a of the rack stopper 8 is pivoted by a pivot 7, and biased on a spring 6b to rotate in the counterclockwise direction in FIG. 2. The arm 6 is actuated by an electromagnet 5 as will be described in more detail hereinafter. A movable shaft 3 extends through an elongated slot 1a of the rack I, which rack is upwardly biased by a spring 12 so that the lower end of slot 1a is caused to abut the shaft 3 connected between pin 1c and fixed shaft 104. Shaft 104 along with shaft 4 is fixed on end plate 101 as shown in FIG. 4.

Referring to FIG.2 illustrating the device in printing position, a rack arm 17 is pivoted on a pivot 17b and normally biased under the force of a tension spring 17a in the clockwise direction so that a ring 17c rotatably mounted to one end of the rack arm 17 is pressed against a cam 14 carried by a cam shaft 15. A link member l7e rotatably mounted by pivot 17d to the other end of the rack arm 17 carries the shaft 3 fitted into the elongated slot la of the rack I through slot 105 in end plate 101 (see FIG. 4).

It is seen that upon rotation of the rack cam 14 the rack 1 which is normally upwardly biased under the force of the spring 12 is caused to move vertically under the control of the rack arm 17 in the guide plate 103 following the movement of shaft 3.

A predetermined number of holes formed through a disk 16 securely fixed to the cam shaft 15 serve to locate rack l and consequently the type bar 2 in desired position coacting with a photoelectric effect element (not shown) so as to print a desired numeral (0 9) or a decimal point upon the paper 10 on the platen 11. This mechanism is not directly related with the present invention so that it will be only briefly described. When a numeral specified by an electronic computer or any other suitable electronic circuit coincides with a numeral specified by the photoelectric effect element, that is coincides with the number of pulses produced by a beam of light passing through the series of holes 16a and incident upon the photoelectric effect element, the electromagnet 5 is energized so that the magnet arm 6 is rotated in the clockwise direction against the spring 6b. In consequence, the pawl 8a of the rack stopper 8 is released from the leading edge 6a of the magnet arm 6 so that the rack stopper 8 is rotated in the counterclockwise direction under the force of the tension spring 8b and then the pawl 8a engages with the tooth b of the rack 1 corresponding to the specified numeral. Since the type bar 2 is vertically moved in unison with the rack 1, it is placed in such position as to print the specified numeral upon the paper 10.

When the shaft 3 coupled to the rack arm 17 which is rotated by the rack cam 14 is raised to its uppermost position, a hammer shaft 18 which also may be operated under the control of a cam on shaft 15 is displaced to a position indicated by the dotted circle 18a. The hammer 9 is thus released and causes the type bar 2 to strike against the platen 11 under the force of a tension spring 9a connected between hammer 9 and shaft 102 fixed on end plate 101, thereby impressing the specified numeral upon the paper 10 through a ribbon 19 interposed between the type bar 2 and the platen 11. A guide plate 13 fixed to end plate 101 has slots 106, 107

and 108 (see FIG. 4) through which hammer 9, rack 1 and type bar 2 respectively move and which serve not only to guide the hammer 9 but also to prevent the lateral vibration of the type bar 2.

FIG.3 shows the device in non-printing position. When there is a digit which is not needed to be printed, that is when it is desired to lock the type bar 2 in nonprinting position, the electronic computer or circuit will not transmit the print signals to the device or will transmit a non-printing signalto the device, so that the electromagnet 5, the magnet arm 6 and the rack stopper 8 are not actuated. In consequence, the rack 1 will be lifted until it is stopped by engagement of extension 1b with the upper end f of a guide plate 20 (see FIG. 2) and the type bar 2 will be raised accordingly to its uppermost position (see FIG. 3). In this case, the detent c of the type bar 2 engages with a bent portion e at the edge of the guide plate 13 so that the type bar 2 is prevented from horizontal movement. Thus when the hammer shaft 18 is displaced to the position 18a, the hammer 9 cannot pivot type bar 2 and is itself held against movement by engagement of bent portion d with slot 2a, because the detent c of the type bar 2 engages with the bent portion e of the guide plate 13. Consequently (as seen in FIG. 3) the type bar 2 is not permitted to strike against the paper 10 over the platen 11. That is, the type bar is locked in a non-printing position.

I claim:

1. A device for use in calculating machines of the type comprising:

a. a series of vertically displacable and settable racks adapted for movement between upper and lower end positions;

b. a series of means for setting said racks at selected positions between said upper and said lower end positions;

c. a series of type bars pivotally connected respectively to said racks for vertical movement and setting therewith;

d. a series of horizontally displacable hammers respectively connected to said type bars for pivoting said type bars when set to the printing position; and

e. a guide plate having openings therein through which said racks, type bars, and hammers pass during displacement;

wherein the improvement comprises:

f. type bar stopper means on said guide plate; and

g. an engaging member on the lower end of each of said type bars for engagement with said type bar stopper means on said guide plate, when a type bar is displaced to its upper end position, By which engagement said type bar is held against pivoting by said respective hammer and is locked in nonprinting position.

2. A device as in claim 1 wherein said engaging member comprises a laterally extending detent on each of said type bars and said type bar stopper means comprises a downwardly bent edge portion of said guide plate. 

1. A device for use in calculating machines of the type comprising: a. a series of vertically displacable and settable racks adapted for movement between upper and lower end positions; b. a series of means for setting said racks at selected positions between said upper and said lower end positions; c. a series of type bars pivotally connected respectively to said racks for vertical movement and setting therewith; d. a series of horizontally displacable hammers respectively connected to said type bars for pivoting said type bars when set to the printing position; and e. a guide plate having openings therein through which said racks, type bars, and hammers pass during displacement; wherein the improvement comprises: f. type bar stopper means on said guide plate; and g. an engaging member on the lower end of each of said type bars for engagement with said type bar stopper means on said guide plate, when a type bar is displaced to its upper end position, By which engagement said type bar is held against pivoting by said respective hammer and is locked in non-printing position.
 2. A device as in claim 1 wherein said engaging member comprises a laterally extending detent on each of said type bars and said type bar stopper means comprises a downwardly bent edge portion of said guide plate. 